#include <stdio.h>
int main(void)
{
    float f_size, dl_speed;

    printf("请输入下载文件的大小(MB)、下载速(Mb/s)： ");
    scanf("%f %f", &f_size, &dl_speed);
    printf("At %.2f megabits per second, a file of %.2f megabytes downloads in %.2f seconds.\n", dl_speed, f_size, f_size * 8 / dl_speed);

    return 0;
}